Synchronizing clock system.



J. W. BRYCE. SYNCHRONIZING CLOCK SYSTEM.

APPLICATION FILED OCT. 4. 1918.

. 1 3 1 0 7 4 Patented July 22, 1919.

UNITED STATES PATENT OFFICE.

JAMES W. BRYCE, OF BINGHAMTON, NEW YORK.

SYNCHRONIZING CLOCK SYSTEM.

Specificationof Letters Patent.

Patented July 22, 1919.

Application filed October 4, 1918. Serial No. 256.799.

State of New York, have invented certain new and useful Improvements in Synchronizing Clock Systems, of which the following is a'full, clear, and exact description.

In a prior application filed by me, Serial N 0. 235,813, filed May 21, 1918, I have'shown and described a synchronizing clock system in which there are combined a master clock and one or more secondary clocks under the control of the former. One of the more prominent features of this system consists in the means employed for maintaining the secondary clock or clocks in approximately perfect synchronism with the master clock,

at least during the working hours when the clocks are in use for the control of such means as time recording devices, between which, or even during such periods, there may occur interruptions in the supply of the morepowerful currents required for the operation of the system. The primary object of the invention was to dispense with a con? tinuously dependable source of current, such as would be afforded by a storage battery or the like,

In the system in question each secondary clock operated circuit controllers by means of which the said clocks were brought at certain times and for definite periods into such operative relationslto the line circuit orra line circuit running from the master clock, that by current transmitted over each circuit for definite periods of the master clock, the secondary clocks out of synchronism would be retarded or accelerated as the case might be, until by their retardation or advance they were brought into exact synchronisin with the master clock, when the synchronizing circuits would be interrupted either by the master or secondary clocks and the latter wouldthereafter run' without control until such time as these circuits might be reestablished;

The invention, subject of the present application, is an improvement on this system, the nature of such improvement, generally stated, being as follows:

In certain systems of this kind the secondary clocks are operated by periodical current impulses transmit-ted to them from and by the master clock, in contradistinction to those which are driven by springs or other local motors wound by hand or by current from the master clock or by current from any other suitable source controlled in its application by the master clock. In such systems the plan of synchronizing outlined in my said former application is not directly applicable without modification, and, primarily, my purpose in this case is to disclose a practicable and effective means for accomplishing this purpose.

To this end, each secondary clock contains two circuit controllers which are operated to furnish paths for current for definite periods bearing a fixed relation to the time as indicated by the clock which operates them. The master clock likewise contains two circuit controllers one of which sends current to line for definite and predetermined periods, and the other of which sends relatively rapid current impulses to line' for certain other definite and predetermined intervals, and the system is so arranged that when the closed period of one of the controllers in the secondary clock overlaps one of the current sending periods from the master clock, the driving mechanismof the secondary clock will be stopped, if that.

clock be too fast, or driven at a rate faster than normal, if it be too slow, until the circuit connectionsare interrupted either by the master or by the secondary clock.

The accompanying drawing is a diagram illustrating at the left the master clock and at the right a secondary clock operated and synchronized by the master clock.

In the master clock 2 indicates the clock train, the driving mechanism not being shown as it is well known. The numeral 3 indicates the escape wheel which is assumed to have a sixty beat rate; 4 is the verge and 5 the shaft on which it is mounted, 6 and 7 beingcontact fingers carried by the shaft.

The shaft of the escape wheel, diagrammatically shown, is marked 8, and carries an arm 9 with an inclined contact 10 at its end with which the finger 6 makes wiping contact once each minute.

similar end contact plate with which finger 7 makes wiping contacts, say, at the rate of ten per minute.

Finally the shaft 12 of the wheel 13 which revolves once an hour, carries two disks 14 and 15, upon the peripheries of which slide double brushes 16 and 17. In the disk 14 The shaft 8 also carries a wheel 11, with a plurality of teeth,

ten or more preferably, each toot-h having, a"

completes a circuit which for simplicitys sake is shown as running from a local battery to one of the two contacts 16, and

' as these contacts at that moment may be assumed to be on one of the contacts 18, the

- circuit is continued through wire 21, back to the battery 20, through an electro-magnet 22.

An energizing impulse through this magnet operates. to throw a pawl carried by its armature through a space suflicient to move a ratchet wheel 23, through an are that moves a. larger ratchet wheel 24 one tooth and brings the high point of a tooth under one of two normally separated contacts 25,

resulting in the completion of a circuit from the main wire 33 through wire 26, to the secondary clock and back therefrom by a common return wire 27;

The ratchets 23 and 24 remain in the condition to complete this circuit until, by the movement of the hour shaft 12, the second contact 18 is brought under contacts 16.

'Thereupon the'ratchets are again moved and the contacts 25 permitted to separate and to break the circuit through wires 26 and 27.

Subsequently one of the contacts 19, by the rotary movement of shaft 12, is brought under brushes 17, whereupon the circuit of the battery 20 is closed through wire 28 to an electro-magnet 29, which operates ratchet wheels 30 and 31, similar to those above described, and closes two contacts 32. This operation closes a break in a circuit including main wire 33, finger 7, contacts 11, and 1 wire 34 running to the secondary clock and back by the common return wire 27.

Again, bearing in mind that the finger 6 contacts with the arm 9 once a minute, it

will be seen that this contact closes a circuit from battery 20 through wire 35, which includes an electro-magnet 36. This magnet when thus energized raises an armature 37 into contact with its back stop and thereby sends an impulse from main wire 33 over wire 38, which runs to the secondary clock. The function of .the master clock as thus described will be hereinafter more fully set forth.

Passing now to the secondary clock, of which there may be any number under the control of the same master clock, 39 is the hour shaft which is rotated step by step by a sixty toothed ratchet wheel 40 operated by apawl 41 and an electro-magnet This magnet is in the circuit of wires 38 trolled by the master clock impulses, is

kept running.

The secondary clock, however, may be called upon to do more than merely indicate time, as, for example, when used to operate or control a time recording device, and hence its load may be considerable, and its liability to miss the intended eifect of one or more impulses is constantly present. It may well happen, therefore, even leaving out of consideration all other disturbing causes, that it may run ahead or behind the master clock. To maintain it at all times, at least during working hours, in synchronism with the master clock I provide the means now to be described.

The hour shaft 39 carries two disks 43 and 44. Disk 43 has a cut-away portion as .shown, and disk 44 has a raised portion. Associated with disk 43 are two contacts 45, which are normally held apart by it, but which are permitted to come together when the cut-away portion is reached. On the other hand, two similar contacts 46 are combined with disk 44, and these are normally separated, but are brought into engagement by the raised portion of the said disk.

The closing periods of the two sets of contacts 45 and 46 are of predetermined length and have a fixed relationto the time indicated by the secondary clock. On the other hand, the closing periods of the contacts 25 and 32 of the master clock, while predetermined as to length by the distance apart of the contacts 18 and 19, occur in fixed relation to true time. Therefore, if these periods in the master clock end at the instants when the corresponding periods in the secondary clock begin, nothing results,

but should they overlap, then the current received from contacts 25, through contacts 45 will pass through wire 47 and electromagnet 48, whose armature breaks the continuity of Wire 38, which includes the driving magnet 42, and hence as long as these 2. conditions exist the clock will stand still.

hour when the current from the master clock ceases.

So with reference to the contacts 46, assuming that they are closed from thirty by way of illustration,

minutes of the hour to fifteen minutes of the hour, these periods being selected merely in the master clock are closed from fifteen minutes of the hour to the hour. If these periods overlap by reason of the secondary clock being too slow, then the rapid impulses comlng over wire 34 from the master clock and returning through the magnet 42 and wire 27 will drive the clock ahead at a faster rate until the circuit is interrupted by either the master or the secondary clock.

This invention is not limited to specific mechanism nor does it include or depend upon the number of circuit wires used, the

other functions of the clocks, or the purposes for .which they may be employed. Broa'dly stated, it. involves the stoppin of an impulse driven clock when it is too ast, and the acceleration of the clock by more frequent impulses when it is too sloW, these operations being dependent upon the estabi lishment of cooperative relations between the two clocks by circuit closing'periods of definite lengths and. at predetermined times according to the indications of the said clocks, in substantially the manner herein set forth. i

Having now described my invention what I claim is:

1. In a clock system comprising a master controllingv and one or more secondary controlled clocks, the combination with each secondary clock of circuit controllers closed for given periods by and in definite relation to the time as indicated by the hands of said controlled clock, means in the master clock for sending driving impulses of current to the secondary clocks, and circuit controllers also in the master clock which are closed for definite and predetermined periods to send, one a continuous current, the other a rapidly intermittent current, to the secondary clocks, and circuit connections between said clocks, whereby when the'periods of closure of the controllers in the master andsecondary clocks overla in time, the secondary clocks will be stopped by the continuous current or rapidly advanced b the intermittent current from the master 0 ock according to be too fast or too slow. I

2. In a clock system comprising a master controlling and one or.m0re seconda controlled'clocks, the combination with the master clock of means for sending to line-periodic driving current impulses, and two ile contacts 32 circuit closers in said master clock, one for sending to line for a given predetermined period a continuous current, the other for sending to line for another given prede termined period a rapid succession of current impulses, circuit controllers in each secondary clock connected with the line circuits and operated for given periods in fixed relation to the time indicated by the hands of the said clock, one of said controllers being adapted to break the circuit of the clock driving means, theother to throw into such circuit the rapidly intermittent urrent from the master clock, when the closure periods of themaster and secondary clocks overlap in time by reason of the secondary clock being too fast or too slow.

3. The combination in a secondary clock of a driving ratchet, a pawl. for the same and an electro-magnet adapted to receive periodic impulses from a, master clock for operating said pawl, an electro-magnet for interrupting the clock driving circuit when energized and two circuit controllers which are closed for given periods in definite relation to the time indicated by the hands of the clock and adapted when closed, one to connect the cut out magnet with a circuit carrying a timed continuous current from the master clock, the other to connect the clock driving magnet with a circuit carrying a time series of rapidly intermittent current impulses, whereby the secondary clock may be stopped or may be rapidly advanced if it be too fast or too slow with reference to the master clock.

4. The method of synchronizing impulse driven secondary clocks with their master controlling clock, which consists in establishing for given periods in definite relation to the time indicated by the hands of the secondary clocks a circuit therein which stops the impulse driving mechanism, and a circuit connected with such driving mechanism and sending from or b the master clock for given periods indeliiiite relation to correct time, a continuous current in one period and; a succession of rapid impulses at another, accelerating the secondary clocks when such periods overlap the periods .of closure in the secondary clocks, according to whether the secondary clocks be too fast or too slow.

In testimony whereof I hereunto aifi'x my signature. i

and thereby either stopping or 

